Degradation of paint and textile industrial effluents by indigenous bacterial isolates

Abstract Untreated paint and textile effluents discharged from industries cause serious environmental threats to fauna and flora. This study thus, investigated the potential of different indigenous bacterial cells for the degradation of paint and textile effluents. Paint and textile effluents samples were aseptically collected from paint and textile industries. Physical, chemical, heavy metals properties and microbial load of the effluent were investigated using standard methods. Enrichment, Isolation and identification of bacterial isolates were determined using the standard microbiological methods. Screening of paint and textile effluents degraders was carried out using solid phase screening method. Degradation of paint and textile effluents were determined by Fourier-transform infrared (FTIR) analysis and spectrophotometrically. Results revealed that among the heavy metals analyzed, lead from paint effluent had highest value of 5.49 ± 1.2 mg/L. All the samples collected were turbid with highest and lowest values of 865 ± 1.3 and 514 ± 2.5 (NTU) from paint effluent samples. Paint effluent also recorded highest bacterial count of 6.85 ± 1.13 CFU/ml while paint sludge had the lowest count of 1.16 ± 0. 15 CFU/g. Forty-seven bacterial isolates were obtained from the paint and textile effluents samples. Screening of the 47 isolates showed that 21 isolates possessed the ability to grow on agar plates amended with paints and textile dyes. Out of the 21 positive isolates, 12 isolates were obtained from paint samples while nine isolates were recovered from the textile samples. Highest degradation activity was recorded by Bacillus subtilis (94.37% ±5.35) obtained from textile effluent sample while Micrococcus sp (46.55% ±8.30) from paint polluted soil sample had the lowest degradation activity. FTIR analysis showed the transformation and disappearance of peaks in the treated paint and textile effluents by Bacillus subtilis. This study revealed the ability and effectiveness of Bacillus subtilis in the removal of toxic materials in paint and textile effluents, thus could be applied for industrial use.